ATS Popular Features and Accessories
John J. Stark
Marketing Services Coordinator, Russelectric Inc.
ATS Timing Features and Important Commonly Used Accessories
Utility/Gen. Time delay to override momentary source 1 power
outages to delay engine start signal and transfer switch operation
(delay for generator start). Programmable 0.0-259 min, factory
set at 3.0 seconds.
Utility/Utility. Time delay to override momentary source 1
power outages to delay transfer switch operation (time delay for
utility sag). Programmable 0.0-30.0 seconds, factory set at 0
seconds.
ATS Timing Features and Important Commonly Used Accessories
Time delay to control contact transition time from neutral to nonpreferred source. Programmable 0.0-10 min, factory set at 1
second.
Time delay to control contact transition time from neutral to
preferred source. Programmable 0.0-10 min, factory set at 1
second.
N
1
L
2
ATS Important Commonly Used Accessories
Load test function (internal) to simulate source 1 power failure.
Remote Load test function energized by 24 VDC signal from
generator control switchgear to simulate source 1 power failure.
Toggle operated load test switch to simulate
source 1 power failure.
Contact closure provided by customer to simulate
source 1 power failure.
Internal form “C” contact to initiate engine starting
or other customer functions (24 VDC Signal by
others)
ATS Timing Features and Important Commonly Used Accessories
Time delay on retransfer to preferred source Programmable 0.0259 min, factory set at 30 minutes.
Programmable function to bypass time delay on retransfer to source 1.
Pushbutton to bypass time delay on retransfer to source 1.
Engine overrun to provide unloaded engine operation after
retransfer to source 1 (delay for engine cool down),
programmable 0.0-60 min, factory set at 5 minutes.
ATS Timing Features and Important Commonly Used Accessories
Load shed function energized by 24 VDC signal from generator control
switchgear to disconnect the load from the source 2 source when an
overload condition occurs. An automatic load shed feature is provided.
Whenever LSF is enabled the source 2 frequency is compared to the load
shed frequency pick-up and drop-out values. When the source 2
frequency is less than the load shed frequency drop-out value 93% (56
Hz) and the load shed timer has expired, then a load shed condition is
initiated. The load shed timer is adjustable from 0-9999 seconds and
factory set at 1 second. Once the source 2 frequency is greater than or
equal to the load shed frequency pick-up value 96% (58 Hz), then the
load shed condition is removed. Ancillary benefit: Dual operator is
beneficial with this design so ATS doesn’t have to load shed to a dead
source.
ATS
24 VDC
ATS Timing Features and Important Commonly Used Accessories
ATS
Block transfer function energized by 24 VDC signal from generator
control switchgear to block or allow transfer to source 2 (typically
generator), so as not to overload it. This accessory includes an
internal programmable function to bypass the block transfer
function, and is used for manual operation. A two-position key operated
selector switch to bypass the block transfer function, may
also be spec’d for manual operation. (Spring return from transfer to
auto.)
24 VDC
Arc Flash, Things to Consider
•External Manual Operator
(EMO)
•Barriered Compartments
(bypass/isolation switches)
•CCDP
•Shutter (bus isolation) Assembly
Can ATS also be manually
transferred safely under load?
•All control
switches
mounted on
outside
•All pertinent
labeling affixed
to the outside of
cabinet, including,
model #, Serial #,
and emergency
phone #